The influence of small cracks in insulating coatings on the flow structure and pressure drop in MHD channel flows
- Institut fuer Angewandte Thermo- und Fluiddynamik, Karlsruhe (Germany)
The use of direct insulations covering the electrically conducting walls is desired when liquid metals are chosen as coolants in fusion reactor blankets. Perfect insulating coatings restrict the path of current to the fluid region. Electric currents induced in the liquid metal due to the interaction of the moving conducting fluid with the plasma confining strong magnetic field close their circuit within extremely thin viscous layers. An additional current path over the conducting blanket walls does not exist for perfect insulating coatings. Thus the total current is minimized and the magnetohydrodynamic pressure drop is essentially reduced below acceptable limits. In the present paper the influence of locally damaged coatings on flow structure and pressure drop is investigated. The effect of partly completely destroyed insulations is most expressed and quite dramatic. The pressure drop may increase by more than one order of magnitude and the flow pattern differ significantly compared to flows in perfectly insulating ducts. However, if the damaged surface area is very small or if the insulating properties are not lost completely the pressure drop is still acceptable and the changes in velocity profiles are restricted only to small regions.
- OSTI ID:
- 196876
- Report Number(s):
- CONF-940664-; TRN: 95:005767-0044
- Resource Relation:
- Conference: ISFNT-3: international symposium on fusion nuclear technology, Los Angeles, CA (United States), 27 Jun - 1 Jul 1994; Other Information: PBD: 1994; Related Information: Is Part Of Third international symposium on fusion nuclear technology; PB: 362 p.
- Country of Publication:
- United States
- Language:
- English
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